1. Field of the Invention
This invention relates to a solenoid of improved construction and to a method for its assembly.
2. Brief Description of the Prior Art
Solenoids intended for use with cyclic voltage supplies have employed a shading ring construction to eliminate noise or chatter caused by bouncing of the armature on the stationary pole during the cyclic variation of the supply voltage. This construction has generally employed a stationary pole piece, a concentric shading ring of an electrically conductive metal and a surrounding, concentric flux ring which is separated by a narrow air gap from the moveable armature when the latter is at its withdrawn position against the fixed pole assembly. The success of this construction critically depends on the spacing of the air gap and prior solenoid manufacturing methods have required precise machining of the stationary pole assembly and the precise positioning of the assembly in the solenoid coil.